Imaging apparatus and image correction method, and image processing apparatus and image processing method

An imaging apparatus comprising:

• an image-capturing element configured such that a phase difference detection pixel for detecting a focus is provided in a part of imaging pixels;
• an optical axis position estimation processor configured to estimate an optical axis position of an optical system configured to form an image of a subject on an image-capturing surface of the image-capturing element, from a pixel output of the phase difference detection pixel and a pixel output of the imaging pixel;
• and
• a pixel correction unit configured to correct pixel outputs of the respective imaging pixels and outputs of the respective phase difference detection pixels in accordance with the relationship,
• wherein the optical axis position estimation processor includes:
• a relationship calculator configured to calculate a relationship between the pixel output of the phase difference detection pixel and an image height, from the pixel output of the phase difference detection pixel and a pixel output of an image pixel near the phase difference detection pixel;
• and
• an optical axis position calculator configured to calculate the optical axis position, from the relationship calculated with respect to each of a pair of the phase difference detection pixels arranged in a detection direction of a phase difference, and
• wherein the correcting unit corrects an influence of optical characteristics of the optical system upon the pixel outputs from the imaging pixel and the phase difference detection pixel, in accordance with the optical axis position calculated by the optical axis position calculator.

An image correction method comprising:

• calculating a relationship between a pixel output of a phase difference detection pixel of an image-capturing element and an image height, from the pixel output of the phase difference detection pixel and a pixel output of an image pixel near the phase difference detection pixel, the image-capturing element being configured such that the phase difference detection pixel, which is configured to detect a focus, is provided in a part of the imaging pixels;
• calculating an optical axis position of an optical system, from the relationship calculated with respect to each of a pair of the phase difference detection pixels arranged in a detection direction of a phase difference;
• storing the calculated optical axis position in a storage unit;
• and
• correcting an influence of optical characteristics of the optical system upon the pixel outputs from the imaging pixel and the phase difference detection pixel, in accordance with information of the optical axis position stored in the storage unit.

An image processing apparatus which processes a pixel output from an image-capturing element including a phase difference detection pixel and an imaging pixel which are arranged in a detection direction of a phase difference between images obtained by dividing a pupil, the apparatus comprising:

• a first pixel output variation detector configured to detect a variation of a pixel output of the phase difference detection pixel and a pixel output of the imaging pixel which has the same color as the phase difference detection pixel and is located in a direction different from the detection direction of the phase difference by the phase difference detection pixel;
• a second pixel output variation detector configured, to detect a variation of pixel outputs between a plurality of imaging pixels which are located near the phase difference detection pixel and the imaging pixel, which were used by the first pixel output variation detector in order to detect the variation of the pixel outputs;
• and
• a pixel correction unit configured to correct pixel outputs of the respective phase difference detection pixels, from results of the first pixel output variation detector and the second pixel output variation detector.

An image processing method for processing a pixel output from an image-capturing element including a phase difference detection pixel and an imaging pixel which are arranged in a detection direction of a phase difference, the method comprising:

• detecting, by a first pixel output variation detector, a variation of a pixel output of the phase difference detection pixel and a pixel output of the imaging pixel which has the same color as the phase difference detection pixel and is located in a direction different from the detection direction of the phase difference by the phase difference detection pixel;
• detecting, by a second pixel output variation detector, a variation of pixel outputs between a plurality of imaging pixels which are located near the phase difference detection pixel and the imaging pixel, which were used by the first pixel output variation detector in order to detect the variation of the pixel outputs;
• and
• correcting, by a pixel correction unit, pixel outputs of the respective phase difference detection pixels, from results of the first pixel output variation detector and the second pixel output variation detector.